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TOPIC 1 Science is … 1

TOPIC 1Science is …

1.1 OverviewThe word science comes from the Latin word scientia, meaning knowledge. For some people it’s an

occupation; for others it’s used to design and build things. But everybody uses scientific knowledge, or

devices made using scientific knowledge — every day.

LEARNING SEQUENCE:1.1 Overview 1

1.2 Science is … everywhere! 3

1.3 The science laboratory 7

1.4 Detective skills 15

1.5 Keeping things under control 17

1.6 Analysing data 22

1.7 Reporting on investigations 26

1.8 Project: Bigger, better beans 34

1.9 Review 36

Numerous videos and interactivities are embedded just where you need them, at the point of learning, in

your learnON title at www.jacplus.com.au. They will help you to learn the concepts covered in this topic.

1.1.1 Think about science • What do scientists do?

• Do people other than scientists use science in their work or leisure activities?

• How is a science laboratory different from other rooms?

• Is the science laboratory a dangerous place?

• Am I a good observer?

• How are substances heated safely in the science laboratory?

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2 Jacaranda Science Quest 7

1.1.2 Your questWhere’s the science?

Work in a small team for this activity. For each of the photographs on this page, work together to write

a paragraph about how scientists might be involved in the activity. Select a spokesperson to read the

paragraph to the class.

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1.2 Science is … everywhere! Science as a human endeavour

Scientifi c knowledge is all around you.

Whenever you turn on a light, eat food,

watch television or fl ush the toilet you

are using the products of scientifi c

knowledge. Nurses, police, dietitians,

teachers, doctors, vets, mechanics,

gardeners, stage designers and artists

use scientifi c knowledge. In fact you

could easily add to this list yourself.

For example, engineers use scientifi c

knowledge to design bridges, com-

puters, factories, artifi cial limbs, sew-

erage systems and buildings.

1.2.1 Science is … biology … the study of living things. There are

many branches of biology. Zoology is

concerned with animals and botany

with plants. Entomology is the study of

insects while microbiology is the study

of living things that are too small to see

without the help of a microscope.

1.2.2 Science is … physics … the study of the behaviour of natural

and manufactured things and reasons

for their behaviour. Physics is con-

cerned with movement and different

forms of energy such as light, heat, elec-

tricity and nuclear energy. Branches of

physics include acoustics , the study of

sound, and biomechanics , the study of

the forces involved in human and other

animal movement.

Think 1. Draw a picture of your own ‘image’ of a scientist on A4 paper.

2. Make a list of the differences between real scientists and the scientist you have drawn. Think about the way

they look as well as what they do.

3. Get together in a group and compare your lists and drawings. Together, compile a group list and draw a

group image or description of a scientist.

4. As a group, suggest one single word that describes what all scientists do.

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WHAT DOES IT MEAN? Psych comes from the Greek word psyche , meaning ‘soul’ or ‘mind’.

1.2.3 Science is … astronomy … the study of the stars, the sun, the planets, their moons and other heavenly bodies such as comets and

asteroids.

1.2.4 Science is … geology … the study of the Earth and how it changes. A geologist might, for example, be concerned with how

mountains are formed or with using rocks to trace the Earth’s history. Vulcanology , the study of volcanoes,

seismology , the study of earthquakes, and palaeontology , the study of fossils, are some of the branches

of geology.

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1.2.5 Science is … psychology … the study of the mind and behaviour. Most psychologists

are concerned with human thought and emotion, but some

work with other animals. Branches of psychology include

sports psychology , which deals with the motivation of athletes,

and forensic psychology , which deals with psychology and

the law.

1.2.6 Science is … chemistry … the study of substances, what they are made of, how they

are formed, how they change and what happens when they are

combined. Branches of chemistry include radiochemistry , the

study of radioactive substances, and pharmacology , the study

of the effect of drugs on living things.

1.2.7 The people of science Scientists can be found just about anywhere. They could be on a riverbank taking water samples, on a boat

fi tting dolphins with radio transmitters to track their movements, searching for fossils in outback cliffs, in a

laboratory searching for the cause of a disease, beside a freeway measuring the effects of sound barriers —

even in space investigating the effects of weightlessness.

HOW ABOUT THAT! Not all scientists were high achievers at school. Some very famous scientists were average or below average

school students. Albert Einstein is probably the most famous example. He did not talk until he was three years

old. He left school at the age of 15 and went back later. He passed his university exams by studying the notes

of his classmates.

Some scientists work in more than one branch. For example, a biochemist works in biology and chem-

istry, studying the substances in living things. A biophysicist might study the small electrical signals that

travel from your ear to your brain, which enable you to hear.

1.2.8 Science and technology Since prehistoric times, people have been making scientifi c discoveries that have improved the quality of

life. The use of scientifi c ideas to design devices that make life easier is called technology . The invention

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of the wheel is a good example of early technology. The scientific idea behind the wheel is that objects roll

over surfaces more easily than they slide across them. The interaction of science and technology has been

the driving force behind our modern technological world.

1.2 Exercises: Understanding and inquiringTo answer questions online and to receive immediate feedback and sample response for every question, go

to your learnON title at www.jacplus.com.au. Note: Question numbers may vary slightly.

Think1. Explain how people in each of the following occupations might use science in their daily work.

(a) Nurse

(b) Mechanic

(c) Gardener

(d) Chef

(e) Architect

(f) Police officer

2. What would each of the following types of scientist be mainly concerned with?

(a) Biochemist

(b) Geophysicist

(c) Marine ecologist

3. List five devices that you have used today that would not have been invented without scientific

knowledge.

Imagine4. Look at the photo of Australian tennis player Lleyton Hewitt. Propose how each of the following scientists

could improve his performance.

(a) Nutritionist

(b) Sports psychologist

(c) Physicist

5. Imagine that you are given the chance to interview any

scientist from the past or present. Who would you choose?

Give reasons for your choice and prepare a list of questions

that you would ask.

Investigate6. What do the initials CSIRO stand for? What does this

organisation do?

7. Find out what you need to study at school and afterwards

to become a scientist or engineer.

Watch this eLesson: Career spotlight: scientist

Meet marine biologist Jodie Haig and learn about this exciting career in marine science.

Searchlight ID: eles-0053

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1.3 The science laboratory

Getting to know the science lab• Sit quietly for a minute or two and look around the science laboratory.

• List as many differences as you can between the science laboratory and other general classrooms

at your school.

• Draw a map of the science laboratory on a sheet of A4 paper, labelling each of the following items clearly.

– student tables and work benches

– teacher’s desk or demonstration bench

– gas taps

– sinks

– eye wash

– fire blanket

– doors

– broken glass bin

– power points

– fume cupboard

– fire extinguishers

– sand bucket

– rubbish bin

1.3.1 Laboratory equipmentSome of the equipment that you are likely to use in the science laboratory is illustrated below.

• Use the illustrations to find each item of equipment in the checklist below. On a copy of the checklist,

place a tick beside each item when you have found it.

Equipment Use

Beaker Container for mixing or heating liquids and other substances

Bosshead Holds the clamp to a retort stand

Bunsen burner Heats substances

Clamp Holds objects at the required height on a retort stand

Conical flask Container for mixing substances or collecting filtered substances

Evaporating dish Container for heating small amounts of substances over a Bunsen burner

Filter funnel Used with filter paper to filter substances

Gauze mat Supports a container over a Bunsen burner while it is heated

Heatproof mat Protects benches from damage

Measuring cylinder Used to measure the volume of a liquid accurately

Retort stand Used with a clamp and bosshead to hold equipment at the required height

Safety glasses Protect eyes

Spatula Used to pick up small amounts of solid substances

Stirring rod Used to stir mixtures

Test tube Container for holding, heating or mixing small amounts of substances

Test-tube holder Holds a test tube while it is being heated

Test-tube rack Holds test tubes upright

Thermometer Measures temperature

Tongs Used to hold small objects while they are heated or to pick up hot glassware

Tripod Supports a gauze mat over a Bunsen burner

Watchglass Holds small quantities of solids

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Watchglass

Filter funnel

Gauze mat

Bunsen burner

Tripod

Heatproof mat

ClampBosshead

Safety glasses

Evaporating dish

Thermometer

Conical flask

Test-tube holder

Stirring rod

Spatula

Test tube

Test-tube rack

Tongs

Beaker

Measuring

cylinder

Retort stand

Some equipment that you are likely to use in the science laboratory:

Parallax error

Measurements should always be made with your eye in line with the reading you are taking. When scales are

read from a different angle, the reading is not accurate. This type of reading error is called parallax error .

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Measuring volume

Liquids in containers such as measuring cylin-

ders are often curved at the top edge. The curve

is called a meniscus. The edges of the meniscus

may curve up or down. We always measure the

volume of liquids from the middle flat section

of the meniscus.

Measuring temperature

A thermometer is used to measure temperature.

The unit of measurement commonly used is

degrees Celsius (°C). The thermometers used in

schools are filled with alcohol, dyed red so that

they are easier to read. When using thermome-

ters, remember these points.

• Never rest the bulb of the thermometer on

the bottom of a container being heated as

the bottom may be hotter than the rest of its

contents.

• Ensure that the liquid for which you are

measuring the temperature fully covers the

thermometer bulb.

• Read the thermometer with your eye level

with the top of the alcohol column.

Reading scales

In science, a scale or set of numbered markings generally accompanies each measuring device. For example,

your ruler measures length, and its scale has markings enabling you to measure with an accuracy of 0.1 cm.

A laboratory thermometer has a scale that measures temperature with an accuracy of 0.5 °C.

When reading a scale, it is important to determine what each of the markings on the scale represents.

Practise reading the scales below.

60 mL

Reading = 57 mL Reading = 56 mL

55

50

45

40

60 mL

55

50

45

40

Measuring

correctly

Measuring

incorrectly

results in a

parallax error.

A 50

40

30

B

24

23

22

C 50

40

30

D

24

23

22

E 25

24

23

F

25

24

23

G

70

80

H

70

80

I

40

50

30

J

40

50

30

The temperatures measured by thermometers A and B are 39 °C and 23.6 °C, respectively. What are the

temperatures measured by thermometers C to J?

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1.3.2 Playing it safeDoing experiments in science can be exciting, but accidents can happen if investigations are not carried out

carefully. There are certain rules that must be followed for your own safety and the safety of others.

Handy hints

• Use a filter funnel when pouring from a bottle or container without a lip.

• Never put wooden test-tube holders near a flame.

• Always turn the tap on before putting a beaker, test tube or measuring cylinder under the stream of

water.

• Remember that most objects get very hot when exposed to heat or a naked flame.

• Do not use tongs to lift or move beakers.

ALWAYS …• follow the teacher’s instructions

• wear safety glasses and a laboratory coat or

apron, and tie back long hair when mixing or

heating substances

• point test tubes away from your eyes and away

from your fellow students

• push chairs in and keep walkways clear

• inform your teacher if you break equipment,

spill chemicals or cut or burn yourself

• wait until hot equipment has cooled before

putting it away

• clean your workspace — don’t leave any

equipment on the bench

• dispose of waste as instructed by your teacher

• wash your hands thoroughly after handling any

substances in the laboratory.

NEVER …• enter the laboratory without your teacher’s

permission

• run or push in the laboratory

• eat or drink in the laboratory

• smell or taste chemicals unless your teacher

says it’s ok. When you do need to smell

substances, fan the odour to your nose with

your hand.

• leave an experiment unattended

• conduct your own experiments without the

teacher’s approval

• put solid materials down the sink

• pour hazardous chemicals down the sink

(check with your teacher)

• put hot objects or broken glass in the bin.

1.3.3 Working with dangerous chemicalsYour teacher will tell you how to handle the chemicals in each experiment. At times, you may come across

warning labels on the substances you are using.

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FLAMMABLEGAS

2

CORROSIVE

8

Always wear gloves and safety glasses when using chemicals with this symbol. Corrosive

substances can cause severe damage to skin and eyes. Acid is an example of a corrosive

substance.

These substances are easily set on fi re so keep them away from fl ames. Methylated spirits is

fl ammable .

Chemicals with this label can cause death or serious injury if swallowed or breathed in. They

are also dangerous when touched without gloves because they can be absorbed by the skin.

Mercury is a toxic substance.

1.3.4 Heating substances Many experiments that you will conduct in the laboratory require heating. In school labora-

tories, heating is usually done with a Bunsen burner. A Bunsen burner provides heat when a

mixture of air and gas is lit.

Bunsen burners heat objects or liquids with a naked fl ame. Always tie hair back and wear safety glasses

and a laboratory coat or apron when using a Bunsen burner.

Heating containers

Beakers and evaporating dishes can be placed straight onto a gauze mat for heating. Never look directly

into a container while it is being heated. Wait until the equipment has cooled properly before handling it.

Use a gauze mat

over a tripod to

hold containers

over a Bunsen

burner flame.

Gauze mat

Tripod

Bunsen burner

Evaporating dish

Heatproof mat

Beaker

A GUIDE TO USING THE BUNSEN BURNER 1. Place the Bunsen burner on a heatproof mat.

2. Check that the gas tap is in the ‘off’ position.

3. Connect the rubber hose to the gas tap.

4. Close the airhole of the Bunsen burner collar.

5. Light a match and hold it a few centimetres above the

barrel.

6. Turn on the gas tap and a yellow fl ame will appear.

7. Adjust the fl ame by moving the collar until the airhole is

open and a blue fl ame appears.

8. Remember to close the collar to return the fl ame to

yellow when the Bunsen burner is not in use.

Base

Barrel

Collar

Airhole

(gas jet inside)

Gas hose

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INVESTIGATION 1.1

Which fl ame is hotter? AIM: To determine which is the hotter part of a Bunsen burner fl ame: blue or yellow

Materials: Bunsen burner matches

pieces of porcelain

clock or watch

heatproof mat tongs

safety glasses

Method and results • Light the Bunsen burner according to the guide above .

• Open the airhole.

• Hold a piece of porcelain over the fl ame with the airhole open.

1. Record roughly how long it takes for the porcelain to turn red-hot.

• Let the porcelain cool on the heatproof mat.

• Close the airhole.

• Hold the porcelain in the yellow fl ame for a few minutes.

2. Describe the fl ame when the airhole is open. What colour is it? Does it make a noise?

3. Describe the fl ame when the airhole is closed. Is it easy to see?

4. Does the porcelain turn red-hot in the yellow fl ame when the airhole is closed?

5. What else do you notice about the porcelain after heating in the yellow fl ame?

6. Which is the hotter fl ame? What observations did you make that support your answer?

INVESTIGATION 1.2

Where is the hottest part of the fl ame? AIM: To locate the hottest part of a Bunsen burner fl ame

Materials:

Bunsen burner nichrome wire heatproof mat tongs matches pin safety glasses

Method and results Part A

• Use a pin to hang an unburnt match over the barrel of a Bunsen burner.

• Light the Bunsen burner according to the guide on the previous page .

• Turn the collar to produce a blue fl ame.

• Turn the Bunsen burner off and remove the match and pin with tongs.

Part B

• Re-light the Bunsen burner and turn the collar to produce a blue fl ame again.

• Use the tongs to hold the wire across the fl ame, close to the barrel of the Bunsen burner, and observe

the wire.

• Move the wire up a little and continue observing.

Unburnt match

Pin

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1. What happens to the match hanging over the barrel? Explain why.

2. What colour does the wire become when held across the fl ame?

3. Is the colour of the wire different when it is held at the top of the fl ame?

4. Draw a diagram of the Bunsen burner fl ame, labelling the parts that are hottest.

Discuss and explain 5. Students often heat substances in a test tube with a Bunsen burner. Why would it be unwise to:

(a) use a yellow fl ame rather than a blue fl ame

(b) position the test tube at the base of a blue fl ame?

6. Why is the yellow fl ame often called the safety fl ame?

INVESTIGATION 1.3

Heating a substance in a test tube AIM: To safely heat a substance in a test tube

Materials:

100 mL beaker Bunsen burner and heatproof mat

matches safety glasses

test tube test-tube rack

test-tube holder food colouring

Method and results

• If you have long hair, is it tied back? • Are you wearing safety glasses? • Is the Bunsen burner on a heatproof mat? • Carefully pour water from a beaker into a test tube to

a depth of about 2 cm as shown in the diagram above.

Add a drop of food colouring to make it easier to see.

• Light the Bunsen burner correctly and heat the test tube

gently in the blue fl ame as shown at right. Remember that

the open end of the test tube should be pointing away

from you and your fellow students. The base of the test

tube should be moved gently in and out of the fl ame. This

prevents the liquid from splashing out of the test tube.

• Once the water has started boiling, stop heating and turn off

the gas to the Bunsen burner. Place the test tube in the test-

tube rack. Leave it there until it has cooled before emptying

it and cleaning up.

Discuss and explain 1. Make a list of any changes you observed inside the test tube

as you heated the water.

2. Why is the test tube placed in a test-tube rack rather than in

your hand?

Pouring a liquid into a test tube

Heating a test tube

CAUTION Before you start heating, check the following:

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1.3 Exercises: Understanding and inquiring To answer questions online and to receive immediate feedback and sample responses for every question, go

to your learnON title at www.jacplus.com.au . Note: Question numbers may vary slightly.

Remember 1. Outline the purpose of each of the following pieces of equipment.

(a) Heatproof mat

(b) Evaporating dish

(c) Test-tube rack

(d) Retort stand

2. Give three examples of equipment used when heating objects.

3. Explain why you should always wear gloves when working with corrosive substances.

4. If the teacher says it is safe to smell a chemical, what technique should you use?

5. Which colour fl ame of a Bunsen burner is hottest — the blue or the yellow?

6. What should you do if you cut or burn yourself in the laboratory?

Think 7. Identify which item of equipment you would use to:

(a) hold a test tube that is to be heated

(b) measure a volume of water exactly

(c) transfer a small sample of a powder to a beaker

(d) mix a sample of powder with water so it dissolves.

8. Look carefully at the picture of students in a laboratory on this page.

(a) Identify at least fi ve dangerous situations you can see.

(b) Explain why each situation is dangerous.

9. The following statements are all incorrect. Rewrite them so that they are correct.

(a) Matches can be safely washed down the sink.

(b) Always point a test tube towards you when heating so you can see what is happening inside it.

(c) Safety glasses need to be worn only when heating over a blue Bunsen burner fl ame.

(d) Water spills do not need to be cleaned up because they are not dangerous.

Create 10. Select one of the safety rules

and choose a strategy for

publicising your message to the

class. You might create a safety

poster, video clip or play.

Danger in the laboratory

Identify the equipment you will need to perform a number of laboratory processes by completing the Using equipment interactivity in your Resources section. int-0200

RESOURCES — ONLINE ONLY

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Complete this digital doc: Worksheet 1.1: The science laboratory

Searchlight ID: doc-19787

Complete this digital doc: Worksheet 1.2: Playing it safe



1.4 Detective skillsCrime scene investigators make observations at the scene of the

crime. A footprint, the smell of perfume, an unusual sound or a

warm log in a fireplace could provide clues to a crime.

The investigators also collect evidence so that they can make

more observations in the laboratory. They use their observations

to make an inference about what happened. An inference is a

suggested explanation of what took place. But inferences are not

always right. Further investigation is usually needed. The investi-

gators often form a hypothesis about what happened. A hypothesis

is an educated guess that can be tested by an experiment, further

observations or measurement. After testing a hypothesis you might

be able to form a conclusion about what happened. A conclusion

is a final explanation of what took place. Sometimes the investi-

gator has to return to the scene of the crime to gather more evi-

dence to make further observations and start the process all over

again before a conclusion can be formed.

The process used by crime scene investigators is used in almost

all scientific investigations. Sometimes scientists form a hypoth-

esis without making an inference first and sometimes no hypoth-

esis is formed before an experiment.

1.4.1 Who or what did this?To solve the mystery shown in the scene below, careful observa-

tions have to be made. Normally you are able to use all five senses

to make observations. However, in this case you can use

only your sense of sight.

1. Look carefully at the drawing and write down as many

observations as you can that might help solve the

mystery.

2. Make an inference about what happened.

3. Form a hypothesis about the mystery that can be tested

by closer observation, measurement or an experiment.

Explain how your hypothesis could be tested by a real

crime scene investigator.

4. Why is it not possible to form a conclusion about who

or what caused the mess using the drawing alone?

Fu

rth

er

ob

serv

atio

ns a

re m

ad

e if

necessary

.

Observationsare made.

Data are collected

in experiments.

A hypothesis is made.

Conclusions are made.

An inference is based on

these observations.

This flowchart summarises

the process of many scientific

investigations.

Who or what did it?

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INVESTIGATION 1.4

Are you a good observer?AIM: To form a hypothesis about observation skills and test it

Materials:

candle and matches jar lid

Method and results• Light a candle and place it on the lid of a jar. Write down as many observations as you can of the burning

candle. Use all of your senses except the sense of taste. No chemicals should ever be tasted in the science

laboratory!

• Michael Faraday (1791–1867), a scientist famous for his discoveries in electricity and chemistry, made 53

observations of a burning candle. Take note of the number of observations you made.

• Use a table like the one below to record the number of observations made by the people in your class.

‘Score’ (number of observations made) Number of people0–7

8–15

16–23

24–31

32–39

40–47

More than 47

• Construct a histogram like the one shown below to display your observations.

1. How many observations did you record?

2. Form a hypothesis about whether you are a better observer than most people in your class.

3. Was your hypothesis supported by the data?

Discuss and explain4. Write a conclusion to answer the question ‘Am I a better observer than most people in my class?’

HOW ABOUT THAT!One of the most famous detectives of all time was Sherlock Holmes. Together with Dr Watson he used

observations and clever hypotheses to solve many crimes. Every hypothesis had to be tested until he could

reach a conclusion about the crime. One of Sherlock’s scientific tools was a simple magnifying glass. Of course,

Sherlock Holmes didn’t really exist — or did he?

A histogram can be used to display observations.

Nu

mb

er o

f p

eop

le

5

4

3

2

1

0

0–7 8–15 16–23 24–31 32–39 40–47

Number of correct observationsMore than

47

CAUTIONDo not touch the flame of the candle.

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1.4 Exercises: Understanding and inquiringTo answer questions online and to receive immediate feedback and sample responses for every question, go


Remember1. How is a scientist like a detective?

2. What is the difference between a hypothesis and a conclusion?

3. Which of your five senses can be used to make observations?

Think4. Explain the difference between an inference and a hypothesis.

5. Read the following ‘story’ and state whether each sentence is an observation, inference or conclusion.

(a) The dog in the house next door is barking.

(b) There are no lights on in the house.

(c) The owners must be asleep.

(d) There could be a prowler in the backyard.

(e) I heard the sound of breaking glass.

(f) The dog is still distressed.

Imagine6. Imagine that you have lost your senses of sight and hearing. Write a description, giving as much detail as

you can, about walking through a remote forest. Don’t forget that your observations can be made only with

your senses of touch, taste and smell.

Investigate7. Sit quietly in a nearby outdoor location and write down all of the things that you notice in two minutes. Use

as many senses as you can, apart from the sense of taste.

(a) Which sense did you use the most?

(b) Compare your observations with those of your friends. Which sense did they use the most?

(c) Which other senses did you use?

Complete this digital doc: Worksheet 1.3: Observing and recording



1.5 Keeping things under controlIn order to answer a question scientifically, a controlled investigation needs to be performed. The inves-

tigation must also be reliable. The simple investigation of bouncing balls described below illustrates how

experiments can be both controlled and reliable.

1.5.1 VariablesThere are many factors that affect how high a ball bounces after being dropped. They include:

• the height from which the ball is dropped

• the type of ball

• the type of surface the ball is dropped onto

• how much the ball has been used

• the method of dropping

• the technique used to measure the bounce height.

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18

These factors are called variables. The variable that you are investigating is called the independent variable. In this investigation the independent variable is the type of ball. You are comparing balls of sim-

ilar sizes made from different materials. The variable that you are measuring (the height of the bounce) is

called the dependent variable.

1.5.2 Fair testingScientific investigations must be fair tests. In a fair test only one variable is changed at a time — the inde-

pendent variable. In this investigation about the tennis ball bounce, that is the type of ball. All variables

other than the dependent variable must be controlled; that is, they must be kept the same. If they were not,

you couldn’t tell which variable was affecting the height of the bounce. You might find it helpful when

designing your own investigations to use a table like the one given below to identify all the variables.

INVESTIGATION 1.5

Bouncing ballsAIM: To plan, conduct and report on a scientific investigation in which variables are controlled

Materials:

tennis ball baseball

rubber ball (about the size of a tennis ball)

any other ball about the same size as a tennis ball

cricket ball one-metre ruler

Method and results• The question you are trying to answer is ‘Which ball bounces the highest?’. Prepare a table in which to

record your results.

1. Write down a hypothesis.

• Take care not to introduce unwanted variables. Make sure that the balls are dropped each time — don’t

accidently give them an extra push down. Also, think about which part of the ball you will measure the

bounce height from.

• You will be working in a small group, so decide who will drop the ball, who will make the measurements

and who will record them.

• Drop each ball from the same height and measure how high each one bounces. Now go ahead and answer

the question — scientifically!

2. Write a report about your investigation using the headings on pages 26–27.

1.5.3 Out of controlSometimes it is not possible to control all of the variables that need to be controlled. These variables

are called uncontrolled variables. These ‘out of control’ variables can make your data unreliable. In the

bouncing ball investigation the size of the ball is uncontrolled. However, the effect of size is minimised by

testing balls of approximately the same diameter.

Independent variable • The type of ball

Dependent variable • The height of the bounce

Controlled variables • The type of surface the ball is dropped onto

• How much the ball has been used (use brand-new balls)

• The method of dropping

• The technique used to measure the bounce height

Investigation: Which type of ball bounces the highest after being dropped on

the ground?

Jacaranda Science Quest 7

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WHAT DOES IT MEAN? The word data comes from the Latin word datum meaning ‘something given’. The English word datum means a

single piece of information. Data means more than one piece of information.

Include a control (left) to test whether wetting a ball (right)

affects how high it bounces.

50 g/L100 g/L

150 g/L

CONTROL:NO SALT

Some investigations require a control group.

1.5.4 Repetition and reliability If you measured the bounce height of each ball only once, your result may not be reliable. Errors often

occur in measurements due to carelessness, a minor change in method (for example in the way the ball

was dropped) or inaccuracies in reading a scale. To reduce the effect of these errors, measurements should

be repeated a number of times and an average calculated. The table below shows an example in which the

bounce height of a wet tennis ball is compared with the bounce height of a dry tennis ball.

The average of these measurements suggests that a dry tennis ball will bounce higher than a wet one. If

you recorded only trial 1, you would form a different — and incorrect — conclusion.

Height of bounce (cm) Trial Wet tennis ball Dry tennis ball

1 47 47

2 45 48

3 42 50

4 42 48

5 44 52

Average 44 49

Comparing the bounce height of wet and dry tennis balls

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1.5.5 Including a controlSome investigations require a control or a control group. For example, you might be investigating the

effects of watering plants with salty water. You could use three different containers of water, each with a

different amount of salt in the water. The independent variable is the amount of salt dissolved in the water.

The dependent variable might be the height of the plant after ten days of watering. For reliability you

observe at least three plants for each amount of salt. To fully investigate the effect of the salt in the water

you need a control group of plants, to which you give water without any added salt. In a control group the

independent variable (the salt) is not applied.



Remember1. What is a variable?

2. Explain the difference between an independent variable and a dependent variable.

3. Why should only one variable at a time be changed in scientific investigations?

Think4. Identify some variables that might affect:

(a) how quickly a pot plant grows

(b) the cost of an overseas airfare

(c) the time it takes you to travel to school in the morning.

5. Advertisements for washing powders and liquids often claim that they are more effective than others.

Imagine that you are conducting an experiment to test a range of washing powders and liquids.

(a) Outline a method for your experiment.

(b) List the variables you will need to control.

(c) What variable will you change?

(d) How will you compare the results of your tests?

6. Amy and Nguyen are trying to find out whether stoneware or glass cups are better for keeping water hot.

The illustration below shows their experiment in progress.

(a) List at least two weaknesses in their experiment design.

(b) Make a list of all the variables that could affect the results of Amy and Nguyen’s experiment.

(c) List any variables that Amy and Nguyen do not need to control.

(d) Write a step-by-step outline of the procedure that they could use to find out which cups are better for

keeping water hot.

Amy and Nguyen’s experiment in progress


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Analyse and evaluateSimon and Jessie performed an experiment to find out how effectively two plastic cups maintain the

temperature of near boiling water. Their data are shown below.

7. Draw a graph to display the data in the table.

8. Which cup maintained the temperature of the water more effectively?

9. Estimate the temperature of the water in Simon’s cup 15 minutes after timing commenced.

10. Use your graph to estimate how long it would have taken the water in Jessie’s cup to drop to a temperature

of 20 °C.

Brainstorm11. In a small group, brainstorm and produce a list of problems that you could investigate scientifically at home

or in the school laboratory without using expensive scientific equipment. You could start by thinking about

investigations involving plants.

Investigate12. Design an investigation to find out whether distances are easier to judge with two eyes than just one. You

can do this by shooting for goal with a basketball or netball from a particular spot under three conditions:

• left eye closed

• right eye closed

• both eyes open.

To produce reliable results, more than one person should take the shooting test and each goal shooter

should have several attempts.

Plan and carry out your experiment. Write a formal report for the experiment including a table of results

and a conclusion. In your discussion section:

• identify the independent and dependent variables

• describe the strategies you used to ensure that this was a fair test.

13. How is the bounce height of a tennis ball affected:

(a) when it is damp

(b) when it is hot

(c) as it gets old and worn

(d) by different tennis court surfaces?

Design and perform an investigation to answer one or more of these questions.

Time (min)

Temperature (°C)

Simon’s cup Jessie’s cup

0 90 90

10 47 58

20 29 39

30 22 31

40 20 26

50 20 23

Comparing plastic cups

Try out this interactivity: Reading scales

Test your skill in identifying temperatures on a number of different thermometers by completing this interactivity in your

Resources section.

Searchlight ID: int-0201

Complete this digital doc: Worksheet 1.4: Developing a fair test


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1.6 Analysing dataValues or measurements obtained from an investigation are called data. Having collected the

data, it is important to present them clearly so that another person reading or studying them can understand

them.

Organising data as a graph is a widely recognised way of making a clear presentation. It makes the

information easier to read and interpret, and makes it easier to show trends and draw conclusions.

A graph, especially a line graph, can also be used to find values other than those used in the investigation.

Line graphs can be used to make predictions. For example, using the line graph on page 24, you can predict

how much salt can be dissolved at temperatures other than those actually measured.

1.6.1 What is a graph?A graph is a diagram that shows the connection between two or more things using dots, lines or bars. There

are four different types of graph: a pie chart or sector graph, a bar chart or column graph, a histogram and

a line graph.

1.6.2 Pie chart (or sector graph)A pie chart (also known as a sector graph) is a circle divided into sections that represent parts of the

whole. This type of graph can be used when the data can be added as parts of a whole. The example below

shows the food types, vitamins and minerals that make up the nutrients in a breakfast cereal.

Complex

carbohydrates

(55.45 g)

Nutrients in 100 g of K-plus cereal

Protein (20.5 g)

Fat (0.5 g)

Niacin (0.02 g)

Iron (0.01 g)

Other B vitamins (0.02 g)

Sugars (18 g)

Calcium (0.5 g)

Fibre (5 g)

A pie chart

1.6.3 Column graph (or bar chart)A column graph (also known as a bar chart) has two axes and uses rectangles (bars or columns) to rep-

resent each piece of data. The height or length of the bars represent the values in the data. The width of the

bars is kept constant. This type of graph can be used when the data cannot be connected and are therefore

not continuous.

The example below shows data on the average height to which different balls bounced during an experi-

ment. Each bar represents a different type of ball. The example on the next page shows the lengths of dif-

ferent metal bars when heated. Each bar represents a different metal bar.


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0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Heights to which different types of ball bounce

Golf ball Tennis ball Basketball

Type of ball

Hei

ght

of

bo

unce

(m)*

* All balls were bounced by the

same person, from the same

height and onto the same

surface.

0 10 20 30

Lengths of different metal bars when heated in the same way

Met

al b

ar

Note: The metal

bars were of

identical lengths

before heating.

Metal A

Metal B

Metal C

Metal D

Length (cm)

Two column graphs (also known as bar charts)

Heights of a group of students in a class

Height (cm)

Num

ber

of

stud

ents

0

5

10

15

20

142 143 144 145141140 146

A histogram

1.6.4 HistogramHistograms are similar to column graphs except that the columns touch each other because the data are

continuous. They are often used to present the results of surveys. In the histogram at the below, each

column represents the number of students that reach a particular height.

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1.6.5 Line graphA line graph has two axes — a horizontal axis and a vertical axis. The horizontal axis is known as the

x-axis, and the vertical axis is known as the y-axis. The line graph is formed by joining a series of points

or drawing a line of ‘best fit’ through the points. Each point represents a set of data for two variables, such

as height and time. Two or more lines may be drawn on the same graph.

Line graphs are used to show continuous data — that is, data in which the values follow on from each

other. For example, the line graph on the below shows the change in the solubility of a salt in water as the

temperature of the water increases. (Solubility is a measure of the mass of a substance that can be dissolved

in a liquid.)

Change in solubility of a salt in 100 mL of water with increasing temperature

Temperature (°C)

Mas

s o

f d

isso

lved

sal

t (g

)

150

100

50

0

302520151050

A line graph



Analyse this1. Prepare a column graph using the following information on the nutrients present in a serving of ice-cream.

2. The following table gives the energy contained in various types of food.

(a) Why are these data not suitable for graphing?

(b) What would you need to do to make them suitable?

Nutrient Amount (g)

Protein 2.00

Fat 6.00

Carbohydrate — polysaccharide 11.00

Carbohydrate — sugars 10.00

Cholesterol 0.02

Calcium 0.10

Potassium 0.80

Sodium 0.05

Nutrients in a 30 g serving of ice-cream


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3. The following table shows the percentage composition of salts present in sea water.

(a) Prepare a sector graph from this table.

(b) Apart from sodium, the salts of which metal are the most abundant in sea water?

4. The following table shows the uses of plastics in Australia.

(a) Select a suitable graph type and prepare a graph from this table.

(b) Choose two uses of plastic from your graph. For each use, state a particular item that is made of plastic.

(c) There has been recent controversy about the waste products that humans create.

(i) Can you suggest any uses of plastics that would contribute to waste products? List them and explain

your choices.

(ii) Can you suggest alternatives to reduce the amount of plastic waste products?

5. Prepare a column graph using the information in the table at right on the amount of energy required by males

and females for various activities.

(a) Why do you think males use more energy per hour than females for the same activity?

Food Energy (calories)

Apple (medium) 75 000

Bread (1 slice) 70 000

Butter (1 tbsp.) 100 000

Chocolate cake (medium slice) 250 000

Cornflakes (1 serving) 75 000

Milk (large glass) 150 000

Orange (medium) 50 000

Sugar (1 tbsp.) 50 000

Energy content of foods

Salt Percentage (%)

Calcium carbonate 0.34

Calcium sulfate 3.60

Magnesium bromide 0.22

Magnesium chloride 10.90

Magnesium sulfate 4.70

Potassium sulfate 2.50

Sodium chloride 77.24

All others 0.50

Salt composition of sea water

Use Percentage (%)

Agriculture 4.0

Building 24.0

Electrical/electronic 8.0

Furniture and bedding 8.0

Housewares 4.0

Marine, toys and leisure 2.0

Packaging and materials handling 31.0

Transport 5.0

Others 14.0

Uses of plastics in Australia

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(b) The following list shows the activities for an average female for one day. How many kilojoules would this

female need to consume to provide the energy for the day’s activities?

(c) If an average male spent a similar day, how much energy would he need?

Complete this digital doc: Worksheet 1.5: Drawing a line graph



Activity Number of hours

Sleeping 8

Light activity 4

Sitting, reading and desk work 10

Gardening 1

Basketball 1

Activity

Energy used per hour by average

female — 58 kg (kJ)

Energy used per hour by average

male — 70 kg (kJ)

Sleeping 240 300

Sitting, reading, desk work and studying 360 450

Light activity, such as driving, playing piano

and standing with only arms moving

480 600

Walking slowly and gardening; working as a

shop assistant or machinist

720 900

Physical work, such as factory or farm

labouring; sports, such as cycling, tennis and

cricket

960 1200

Heavy physical work, such as loading, stacking

and carrying; vigorous sports, such as jogging,

basketball, hockey and football (activity that

leads to sweating)

1440 1800

Very heavy physical work and vigorous

sports, such as football, hockey, running and

swimming (activity that causes free sweating,

requiring short bursts of extreme energy)

2400–4800 3000 –7200

Amount of energy required for various activities

1.7 Reporting on investigationsWhen scientists conduct investigations, they need to write reports to tell other people about their work.

When you conduct experiments, you need to write reports that allow others to understand what you did and

to read about what you found out.

Your reports should include the following sections.


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Aim

A statement about why you did the experiment

Materials

A list of the equipment and chemicals that were used

Method

An account of what was done. This will usually include a diagram showing how your equipment was set

up. There should be enough details included to allow the reader to repeat your experiment.

Results

A presentation of your data. This might include a list of observations, or tables and graphs.

Discussion

An explanation of your results and a

description of any difficulties you had with

the experiment. This section might also

include suggestions for improvements to the

experiment.

Conclusion

A brief account of what you found out and

how your findings relate to your aim. It is a

good idea to read your aim again before you

write your conclusion.

1.7.1 Drawing science equipmentWhen reporting your experiments, a good,

simple diagram can make it much easier

for the reader to understand what was done.

There are some rules to remember:

1. Diagrams in scientific reports should be

drawn in pencil.

2. Straight lines should be drawn with a

ruler.

3. Each item of equipment should be

labelled.

The following diagram shows how some

commonly used items of equipment should

be drawn.

1.7.2 Organising observations and dataWhen making a lot of observations, it is

often helpful to organise them in a table.

Observations and measurements that are

organised in tables are easier to read. Tables

also make it easier for you to draw graphs.

Tripod and gauze mat

Bunsen burner and heatproof mat

Beaker

Conical flask

Test tube

Retort stand, bosshead and clamp

Filter funnel and filter paper

Diagrams in scientific reports should be simple. In each

case above, the apparatus is shown on the left and the

diagram of this apparatus on the right.

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INVESTIGATION 1.6

Recording observations in a tableAIM: To record method and observations of simple experiments in a table

Materials:4 test tubes test-tube rack50 mL beaker spatulaeye-dropper drinking strawvinegar sodium bicarbonatesodium carbonate copper sulfatemethylated spirits limewaterstarch suspension iodine solutionsafety glasses

Method and results

1. Draw a table like the one below to record your observations in each of the following activities.

Activity 1• Pour vinegar into a clean test tube to a depth of about 1 cm. Add a spatula full of sodium bicarbonate.

Activity 2• Quarter-fill two clean test tubes with water. Add a dry spatula full of sodium carbonate to one test tube.

Shake the tube until the sodium carbonate dissolves. Add a dry spatula full of copper sulfate to the other

test tube and shake it until the crystals dissolve. Pour the contents of the second test tube into the first.

Activity 3• Use an eye-dropper to put one drop of methylated spirits onto the back of your hand. Blow air gently

across the back of your hand.

ActivitySummary of what

was done Observations

1

2

3

4

5

CAUTIONSafety glasses should be worn while conducting these experiments.


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Activity 4• Quarter-fill a very small beaker with limewater. Gently blow out through a drinking straw into the limewater.

Be careful not to share straws.

Activity 5• Put a few drops of starch suspension in a clean test tube. Add a drop of iodine solution.

Discuss and explain2. What senses did you use in making your observations?

3. Describe two safety precautions involved in this investigation.

4. Explain why it is important to use small quantities of chemicals when doing experiments like these.

5. Explain why it is useful to present the observations in a table.

6. In activity 4, you had to pour limewater into the beaker. If you took more limewater than required, why it is

not a good idea to return any unused limewater to the original bottle?

INVESTIGATION 1.7

Graphing temperatureA line graph is a useful way to present the results of an experiment and gives an overall picture of the results.

A line graph can also be used to predict values that occur between, or outside, those measured during an

experiment.

AIM: To observe how the temperature of water changes while it is heated over a Bunsen burner

Materials:100 mL measuring cylinder 250 mL beakerBunsen burner heatproof matmatches tripodgauze mat stopwatchsafety glassesretort stand, bosshead and clampthermometer or data logger and temperature sensor

Method and results• Use a measuring cylinder to measure 100 mL of water.

• Pour the water into the beaker.

CAUTIONTake care not to get iodine solution on your skin or clothes.

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• Set up the equipment as shown in the diagram. Make sure that the bulb of the thermometer is not on the

bottom of the beaker or out of the water.

• Wait for a minute to allow the thermometer to adjust to the water temperature.

1. Measure the initial temperature of the water and record it in a table. The initial temperature is recorded when

time is 0 minutes.

• Put your safety glasses on.

• Light the Bunsen burner according to the guide on page 11.

• Open the airhole and heat the beaker over a blue flame.

2. Measure and record the temperature of the water every minute

for 10 minutes.

• Turn off the Bunsen burner and allow the equipment to cool.

3. Plot a line graph of the data you have collected on a sheet of

graph paper using labels like those below.

4. Draw a smooth line near as many points as possible to show the overall trend in the water temperature

over time.

Discuss and explain5. Why didn’t you record the starting temperature of the water as soon as you poured the water into the

beaker?

6. Describe in words how the temperature increased.

7. How does your graph compare with those of other groups?

8. Predict what would happen to the temperature of the water if you continued heating for another two minutes.

Time (min) Temp (°C) Time (min) Temp (°C)

0 6

1 7

2 8

3 9

4 10

5

100

90

80

70

60

50

40

30

20

10

0 1 2 3 4 5 6 7 8 9 10 11 12

Tem

per

atur

e (°

C)

Time (minutes)

Retort

stand

Bosshead

Thermometer

Beaker

Gauze

mat

Tripod

Bunsen

burnerMatches

Clamp

Heatproof mat


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1.7.3 Using technology: spreadsheetsA spreadsheet is a document that stores data

in columns and rows. Spreadsheets used to be

written on paper by hand. Shopkeepers and

bank tellers needed to keep neat handwritten

ledgers to record all transactions. Today, com-

puters and software such as Microsoft Excel

are used to create and edit spreadsheets.

Spreadsheets can also be used to create graphs

and charts at the click of a button.

Some spreadsheet terminology

In a spreadsheet, the data are organised in

rows and columns. The columns are named

using letters (such as column B) and the rows

are named using numbers (such as row 3).

Cells are the boxes in the spreadsheet. The

cell reference tells us which column and

row the cell is in. For example, cell B3 is in

column B and row 3. The active cell is the

cell you will type the data in. In Excel, it has

a dark border around it. This is shown in the

diagram below.

Working with Excel spreadsheets

When you create a spreadsheet, you need to

decide how many columns and rows you will

need and enter a suitable heading for each

column. This is similar to designing a table.

Make sure that you include units where rel-

evant. When using Excel, you can format cells

in a variety of ways by using the Format tool.

A good quality report of an experiment

Cell B3 is the active cell.

Entering formulae in Excel

If you want to do calculations on the data in a spreadsheet, you need to enter a formula. In Excel, a formula

always starts with an equals sign (=). If you want the total of cell A2 and cell B2 to appear in cell C2, you

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would type the formula ‘=A2+B2’ in cell C2, and then press the Enter key. You can also use one of the

many functions available in Excel. For example, it is much quicker to use the Average function to calculate

the average of 50 numbers than to type in a formula to add the 50 cells and divide the total by 50. The

Insert function button, fx , can be used to view the format required for particular functions.

Drawing graphs and charts

Drawing a graph using Excel is easy. Just highlight the data you want to graph, click on the Insert tab,

select the type of graph you want to draw and then follow the prompts. Remember that a scatter graph

(XY chart) is used to plot one set of values against another in Excel.

1.7 Exercises: Understanding and inquiring To answer questions online and to receive immediate feedback and sample response for every question, go

to your learnON title at www.jacplus.com.au . Note: Question numbers may vary slightly.

Remember 1. Explain why scientists write reports about their experiments.

2. Under which heading of your report of an experiment should the following information be included?

(a) Suggestions for improvements to your experiment

(b) A reason for doing the experiment

(c) Graphs and tables

(d) A description of what you did

(e) A statement saying what you found out by doing the experiment

3. Draw a neat, labelled scientifi c diagram of the following equipment. Water in a conical fl ask is being heated

with a Bunsen burner. The conical fl ask is supported by a gauze mat on a tripod. The Bunsen burner is

standing on a heatproof mat.

B G

H

A

F

E

C

D


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Understand4. In the screenshot below, identify the letter pointing to:

(a) cell C2

(b) cell E5

(c) the active cell

(d) a formula

(e) the Insert scatter graph button

(f) the Insert function button

(g) a column

(h) a row.

5. List two advantages and two disadvantages of using a computer spreadsheet program to store data rather

than keeping handwritten records in a book.

Think6. Write a full scientific report on Investigation 1.7.

7. Draw a neat, labelled scientific diagram of the two sets of equipment that would be needed to safely perform

the following activity.

Part 1:Muddy salt water is being poured from a beaker into a filter funnel (with filter paper). The filter funnel is

resting in the opening of a conical flask.

Part 2:The filtered salt water, now in an evaporating dish, is being heated by a Bunsen burner. The evaporating dish

is supported by a gauze mat on a tripod.

8. A hypothesis is often included in a scientific report — usually under the ‘aim’ heading, immediately after the

reason for carrying out the experiment. What is a ‘hypothesis’?

Investigate9. Design an experiment to investigate whether adding salt to water changes how the temperature rises when

the water is heated. Write a scientific report outlining the design of your experiment.

Analysing data10. (a) Create a spreadsheet with the column headings ‘Time (min)’ and ‘Temperature (°C)’. Enter your data from

Investigation 1.7. You should end up with a table similar to the one below.

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(c) Create a title for your graph. Label the x-axis ‘Time (min)’ and the y-axis ‘Temperature (°C)’. You should

obtain a graph similar to the one below.

11. Use the graph from question 10 to answer the following questions.

(a) For how long did the experiment run?

(b) What was the temperature of the water when the experiment began?

(c) How long did it take for the water to boil?

(d) How many readings were taken?

(e) What would you expect the graph to look like after 10 minutes?

(f) How would you expect the graph to change if only 50 mL of water was heated?

(g) Sketch a graph of what the predicted results would be for a 200 mL beaker of water. Perform the

experiment to check your predictions.

Create12. (a) Collect the following data for each student in your class.

(i) First name

(ii) Gender

(iii) Foot length (cm)

(iv) Height (cm)

(v) Favourite subject

(vi) Country where mother was born

(b) Enter the data you collected into a spreadsheet.

(c) Click on the Insert tab, then use the Chart function button to construct a scatter graph (without joining

points) showing foot length on the x-axis and height on the y-axis.

(d) Use your graph to decide whether there is a relationship between foot length and height.

Tem

per

atur

e (°

C)

Time (min)

Heating 100 mL of water

100

80

60

40

20

0

0 2 4 6 8 10 12

120

Temperature

1.8 Project: Bigger, better beans

1.8.1 ScenarioThe local agricultural show will be running its annual competition to find the biggest bean plant and you

are determined that this year you are going to win. In previous years, you have just planted your seeds in

their pots, added some fertiliser, put them in the sun and watered them every day but, while the plants did

grow, they didn’t grow big enough to have a chance at the prize. As a good science student, you know that

the growth of plants depends upon the process of photosynthesis, whereby light energy from the sun causes


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water and nutrients and carbon dioxide to be combined by the plant to produce oxygen and starch (which

is a form of chemical potential energy). The plant then uses this starch to grow. So, if the growth of the

plants depends upon how much starch is produced, maybe there’s something you could do to the plants that

would make them produce more starch and grow faster and bigger?

1.8.2 Your task You will design and carry out an investigation that will test a number of different growth conditions (for

example, different amounts of sunlight or different substances added to the soil) to determine which will

give the greatest rate of growth over a three-week period of time. Your fi ndings will be presented in the

form of a scientifi c report.

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1.8.3 ProcessOpen the ProjectsPLUS application for this chapter located in

your eBookPLUS. Watch the introductory video lesson and then

click the ‘Start Project’ button to set up your project group. You

can complete this project individually or invite other members

of your class to form a group. Save your settings and the project

will be launched.

Watch this eLesson: Growing plants in Australia

This video lesson is presented by a top Australian horticulturalist and provides you with tips for successfully growing

plants in Australia. Watch this video as an introduction to your experiments with plants.

Searchlight ID: eles-0055

ONLINE ONLYRESOURCES — ONLINE ONLY

1.9 Review

1.9.1 Science as a human endeavour • describe how science is used in a range of occupations

• outline some of the branches of science and how they affect everyday life

• distinguish between science and technology

1.9.2 Introducing the laboratory • identify and safely use a range of equipment to perform scientific investigations and collect data

• describe ways to reduce the risk to yourself and others in the laboratory

1.9.3 Planning and conducting investigations • make inferences and testable hypotheses in the light of observations and measurements

• describe a logical procedure for undertaking a controlled experiment

• use repetition of measurement to increase the reliability of data

• form conclusions based on experimental results

• reflect on your methods and make suggestions for improvements to your investigations

• use a scientific report with clear diagrams where necessary to describe your investigations

and their findings


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1.9.4 Processing and analysing data and information • make and accurately record observations and measurements using the appropriate equipment

• organise data clearly using tables

• construct an appropriate type of graph (e.g. column graph, pie chart, line graph) to present your data

• use tables and graphs to identify trends and patterns, and assist in the formation of conclusions

• identify data that support or discount a hypothesis

Individual pathways

ACTIVITY 1.1Investigating

doc-6075

ACTIVITY 1.2Analysing investigations

doc-6076

ACTIVITY 1.3Designing investigations

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1.9 Review 1: Looking backTo answer questions online and to receive immediate feedback and sample response for every question, go


1. Match the following scientists with their work.

2. What does each of the following scientists study?

(a) Seismologist

(b) Biochemist

(c) Entomologist

(d) Botanist

(e) Zoologist

(f) Vulcanologist

3. Which of the scientists listed in question 2 could be correctly described as geologists?

4. Indicate whether each of the following actions is a ‘do’ or a ‘don’t’

in the science laboratory.

• Wear safety glasses while mixing chemicals.

• Pour all substances down the sink when finished with them.

• Run in the science laboratory.

• Drink water from the taps in the science laboratory.

• Tie long hair back before using a Bunsen burner.

• Wait until the end of the lesson to tell your teacher that you have

burnt yourself.

5. Write a list of all of the equipment that you would need to boil

water in a beaker in your science laboratory. Draw a labelled

scientific diagram to show the equipment in use.

6. Copy this diagram of a Bunsen burner and complete all of the

missing labels.

Scientist Work

(a) Physicist (A) Investigates how rocks and mountains form

(b) Chemist (B) Studies living things

(c) Biologist (C) Explains things like movement, heat and light

(d) Astronomer (D) Studies how substances react with others

(e) Earth scientist (E) Studies the sky

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7. Rewrite the following sentences correctly by selecting the appropriate words in italics.

(a) When lighting a Bunsen burner, light the match before/immediately after turning on the gas.

(b) When using a thermometer to measure the temperature of a liquid as it is heated, place the bulb of the

thermometer on the bottom/near the centre of the beaker.

(c) When heating a test tube, hold the test tube using tongs/a test-tube holder at the top/middle of the test

tube and keep it steady/move it back and forth over the flame.

8. The steps used to light a Bunsen burner can be displayed as a flowchart, as shown below. Use the

information in the flowchart to construct a storyboard with six scenes to show how a Bunsen burner is lit

correctly and safely.

9. Name each of the items of equipment

below.

10. Kimberley and Glenn were walking past

their neighbour’s house when they noticed

that a front window was broken. Glenn told

Kimberley that somebody had probably

thrown a ball through the window. They

had a closer look and noticed clothes

scattered all over the floor and drawers

open. Kimberley noticed some blood on the

broken glass. She told Glenn that the house

had been burgled. Glenn agreed and they

called the police.

(a) List the observations that were made.

(b) Who made an inference?

(c) What was the inference and why was it

suggested?

(d) What conclusion was reached by Kimberley and Glenn?

(e) Suggest a different conclusion based on the observations that were made.

11. What item of equipment would you use to measure:

(a) the temperature of hot water

(b) the mass of a small beaker of water

(c) the volume of a small quantity of water?

Lighting a Bunsen burner

Place the Bunsen burner on a heatproof mat.

Light the match.

Ensure that the airhole is closed.

Open the gas tap.

Hold the burning match just above the top of the barrel.

Check that the rubber tubing is connected properly to

the gas tap.

(a) (b) (c)

(d) (e) (f)


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12. Identify the temperature measured by each of the thermometers shown below.

13. The following graph shows how far from the starting point a snail moves in an experiment.

(a) Calculate how far from the starting point the snail was 7 minutes after timing began.

(b) During what times did the snail not move at all?

(c) What does the graph tell us about the snail’s movement between 7 and 8 minutes after timing began?

(d) Propose why a smooth line was not drawn in this graph.

14. Identify which of the following is an important safety rule in science.

(A) When smelling chemicals, place your nose carefully over the container.

(B) Dispose of all materials in the rubbish bin.

(C) When reading the volume of a liquid, always read the bottom of the meniscus.

(D) Point test tubes away from your eyes and away from your fellow students.

15. Equipment used for measuring the volume of liquids includes:

(A) conical fl ask, beaker, measuring cylinder.

(B) measuring cylinder, crucible, beaker.

(C) watchglass, fi lter funnel, conical fl ask.

(D) evaporating basin, test tube, beaker.

16. Luke was sick and tired of being bitten by mosquitoes. He counted several bites each evening when he sat

outside to have dinner. He had heard that a burning citronella candle was a good way to keep mosquitoes

away. Design an experiment to test Luke’s idea. Identify the independent and dependent variables and the

controlled variables needed to make this a fair test. Suggest a control for your experiment.

17. Huang and Tina conducted an investigation to fi nd out whether radish plants grow better in the shade. They

placed three seedlings under a verandah at the back of the house and another three in a sunny place in

the front yard. All plants were planted in the same soil and were watered equally each day. Huang and Tina

measured the height of each plant and the number of healthy leaves at the same time every second day.

(a) What was the independent variable in the investigation?

(b) What were the dependent variables?

90

80

70

18

17

16

(a) (b)

0

0

5

10

15

20

25

30

Dis

tanc

e fr

om

sta

rtin

g p

oin

t (c

m)

Time (min)1 2 3 4 5 6 7 8

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Complete this digital doc: Worksheet 1.6: Designing an experiment


Complete this digital doc: Worksheet 1.7: Checklist



Link to assessON for questions to test your readiness FOR learning, your progress AS you learn and your levels OF achievement.

www.assesson.com.au

(c) List the variables that should have been controlled.

(d) How could Huang and Tina improve the design of their experiment? List as many improvements as

possible.

(e) In your opinion, did Huang and Tina conduct a fair test? Give reasons for your opinion.

18. Now that you’ve spent some time working on this chapter, think about the best way to describe a scientist.

(a) Draw a picture of your own image of a ‘typical’ scientist.

(b) Write your own description of a ‘typical’ scientist.

(c) Write a comment about how your image of a scientist has changed since you started working on this

chapter.


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